1. Field of the Invention
This invention relates to a drive for a floppy disk as used for external storage in personal computers and a word processors, and more particularly to the reduction of thickness of a floppy disk drive.
2. Description of the Prior Art
A conventional 3.5 inch type floppy disk drive is shown in FIGS. 14-16. Referring to FIG. 14, a reference numeral 1 denotes a chassis, to the front surface (left side in the drawings) of which a front panel 2 is attached, a disk holder 3 being provided in the interior of the chassis 1. The disk holder 3 has pins 4, 4, 4, 4 projecting from the front and rear portions of the left and right side surfaces thereof, and cam recesses 6, 6, 6, 6 are made in a slider 5 provided slidably between the chassis 1 and disk holder 3, in which cam recesses 6, 6, 6, 6 the pins 4, 4, 4, 4 are inserted loosely so as to support the slider 5 horizontally. A carriage 7 is provided on the rear portion of the chassis 1, and a pair of magnetic heads 8, 9 are supported thereon.
As shown in FIG. 15, the carriage 7 in the conventional drive consists of an upper support arm 12 capable of being moved vertically by a plate spring type resilient member 11 attached to the upper portion of a base body 10 of the carriage 7, and a lower support arm 13 extended from the carriage base body 10. A magnetic head 8 is fixed to the front end portion of the upper support arm 12, and a magnetic head 9 to that of the lower support arm 13.
In the floppy disk drive in the condition shown in FIG. 14, a part of the upper support arm 12 is engaged with the upper surface of the rear end portion of the disk holder 3, and the upper and lower magnetic heads 8, 9 are maintained in a largely separated state. When a floppy disk 15 is inserted into an insert port 14 in the front panel 2, the front end portion of the floppy disk 15 presses up a shutter 16 in the insert port, so that the floppy disk 15 is held in the disk holder 3. When front end portion of the floppy disk 15 has then contacted a stopper arm 17, the stopper arm 17 is turned back and disengaged from a locking member 18, and the slider 5 is moved slidingly in the forward direction owing to a tensile force of a spring 19.
During this time, the pins 4, 4, 4, 4 in the cam recesses 6, 6, 6, 6 are pressed down, and the disk holder 3 is lowered as it is kept horizontal as shown in FIG. 16, with the floppy disk 15 which is held in the disk holder 3 lowering in the direction of an arrow A in FIG. 15, whereby the lower surface of the floppy disk 15 engages the magnetic head 9, the floppy disk 15 being thus positioned. The upper support arm 12 locked by the rear end portion of the disk holder 3 is turned in the direction of an arrow B in the same drawing due to a pressure from the spring 20, and the upper surface of the floppy disk 15 contacts the magnetic head 8. The upper and lower magnetic heads 8, 9 thus contact the upper and lower surfaces of the floppy disk 15 to set the floppy disk 15 so that the reading and writing can be done.
In order to take out the floppy disk 15 in this condition, an ejection button 21 on the front panel 2 is pressed to provide an operation reverse to those mentioned above, so that the disk holder 3 moves up and regains the condition shown in FIG. 14, the floppy disk 15 being discharged via the insert port 14 in the front panel 2.
Since the disk holder 3 in the conventional floppy disk drive is moved vertically as it is kept horizontal as mentioned above, it is necessary to allow for a predetermined vertical stroke of the disk holder. When the disk holder 3 is in a lifted position, the free end portion of the upper support arm 12 is turned up to a position higher than the upper edge of the disk holder 3 so as to prevent the floppy disk 15 inserted into the disk holder 3 from contacting the upper support arm 12. In order to turn up the upper support arm 12 so that it has a sufficient clearance between the free end portion thereof and the upper edge of the floppy disk 15, it is necessary that a range of a vertical movement of the disk holder 3 be set large. Consequently, the thickness of the chassis 1 increases, and the reduction of thickness of the floppy disk drive is restricted.
A technical problem to be solved for minimizing the range of vertical movement of the free end portion of the upper support arm to reduce the thickness of the chassis as well as that of the floppy disk drive. It is an object of the present invention to solve this problem.